1. Field of the Invention
The present invention relates to a projector and a projection image correction method thereof.
2. Description of the Related Art
A projector (projection arrangement) is an apparatus for displaying an image on a screen. If the optical axis of the projector is inclined with respect to the screen surface, the image displayed on the screen surface is distorted. To avoid this, as disclosed in Unexamined Japanese Patent Application KOKAI Publication No. 2000-122617 (pp. 4 to 7, FIG. 1 and FIG. 2), there has been proposed a projector having a trapezoidal correction unit which corrects a distortion of a projection image based on an inclination of the optical axis of the projector with respect to the screen surface, so that despite of this inclination, an undistorted image will be displayed on the screen surface.
Some projectors have a zooming mechanism. The trapezoidal correction unit of a projector having a zooming mechanism performs trapezoidal correction after the zooming magnification is set.
Conventional projectors have to perform trapezoidal correction twice, because the first trapezoidal correction made based on the angle of inclination is canceled if the zooming magnification is changed.
The present invention was made in consideration of the conventional problem, and an object of the present invention is to provide a projector and a projection image correction method thereof which are capable of appropriately performing correction of a projection image even if the zooming magnification is changed.